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ADEQUACY CHECK OF LAG SCREWS AND <br />EXISTING FRAMING DUE TO WIND FORCES <br />TYPICAL PROFILE: <br />Wind Pressure, P <br />4 ev + 41 1 <br />= 24' O-c·rafter spacing rafter spacing <br />V <br />= 24" o.c. <br />>ICN=rC <br />Legend: <br />1. Exisiting 2x6 Roof Rafter w/ purlin supports (Total Span of 17 ft) <br />2. Solar Panel Track Rail <br />3.5/16 inches dia. Lag Screw w/Min. 2.5"PenetrationintoRafter <br />Uplift from Solar Panel Wind Forces, U <br />Design Wind Pressure, P = <br />Trib. Depth for Each Rail, Td = <br />Screw Anchor Spacing, S = <br />Resisting Weight of Panels, D = TdxS*3 psf = <br />Uplift Force on Each Screw, U= PxTdxS -D= <br />Check Adequacy of Laq Screw for Pull-Out <br />-30.9 psf (See Attached Wind Analysis) <br />2.75 ft (5.5 ft + 2) <br />4 ft (max.) <br />33 lbs <br />-306.9 lbs (Upwards) <br />'-Uplift Resistance Provided by 5/16 inches dia. Lag Screw with Minimum 2.5 in. <br />Penetration into Douglas Fir Larch Member Per NDS (Table 11.2A) =266 lbs/in <br />Allowable Uplift Load, Ua = 1.6 x 2.5 x266 =1064 lbs >U= 306.9 lbs 4 OKAY <br />Existing Framing Member Check* <br />purlin span <br />Roof Dead Load <br />Panel Deal Load <br />Total Dead Load, DL <br />Screw Uplift Loads, W <br />8.5 ft o.c. <br />12 psf <br />3 psf <br />15 psf x 2 feet spacing =30 pif <br />-306.9 lbs (Max. 4 Anchors/Stand-offs on Rafter) <br />*See attached Enercalc Output for Analysis Results